Electrical batteries are used to store and supply energy for electrical systems. Vehicles, operating at least partially on electrical power, have a battery pack installed. The battery pack consists of a plurality of batteries connected in a series string to establish a high voltage electrical power source. When used as the primary or sole energy source in automotive vehicles, it has become common to use several battery modules, each providing 12 volts, that are connected in a series string to form a battery pack having a high voltage output.
The battery pack generally terminates at a high voltage connector receptacle into which a harness connector is installed. This receptacle is located on an exterior surface of the casing in which the battery pack is housed. The harness delivers power to various parts of the vehicle, including the drive motors. It is common practice to provide a disconnect mechanism between the battery pack and the receptacle to insure that the harness is neither installed in or removed from the receptacle prior to the battery pack being disconnected. This eliminates the possibility that service personnel will come into contact with the high voltage energy source when manipulating the harness or that arcing will occur when the disconnect mechanism is properly actuated.
The electrical disconnection of the battery pack from the receptacle has commonly taken two forms--manual and automatic disconnect mechanisms have been employed. The manual disconnect mechanism is generally installed at or near the midpoint of the battery string. The disconnect mechanism is generally in the form of a handle which serves as a switch to break the electrical connection. When the handle is pulled, a physical break in the battery string is occasioned to thereby interrupt the electrical connection between the battery pack and the harness connector. The disconnect mechanism is provided so that anyone removing the harness connector will not come into contact with the high voltage source.
The automatic disconnect mechanism interrupts the battery string by employing electrical sensors and algorithms that determine the conditions under which the battery pack should be disconnected from the connector. Upon sensing a fault condition, the battery pack is shut down, with software commands, and checked to determine that proper handling conditions exist. This type of disconnect mechanism is performed by electrical switching and typically does not employ mechanical disconnection devices. While both type of disconnect mechanisms are effective, they do not prevent inadvertent contact with the high voltage output of the battery pack at the connector receptacle.